Thurs·day (thûrzdē, -dā′)
n. Abbr. Thurs. or Thur. or Thu. or Th or T
The day of the week that comes after Wednesday and before Friday.
[Middle English, from Old English thūres dæg, alteration (influenced by Old Norse thōrsdagr, Thor's day) of thunres dæg, Thor's day (translation of Late Latin Iovis diēs, Jupiter's day) : thunres, genitive of thunor, thunder; see (s)tenə- in the Appendix of Indo-European roots + dæg, day; see DAY.]
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Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.